Inches to CM Converter

An inch is exactly 2.54 centimeters, so the conversion is one multiplication:

centimeters = inches × 2.54

Nothing is rounded in that factor. The 1959 international yard and pound agreement defined the inch in metric terms rather than the other way round, which is why every inch-to-cm result is exact to as many decimal places as you care to take it.

Most people arrive here from an American spec sheet. Three cases come up constantly:

Screen sizes. A "27-inch" monitor is measured diagonally, not across, so 27 × 2.54 = 68.58 cm describes the diagonal only. A 16:9 panel that size is about 59.8 cm wide — check the width before assuming it fits a shelf.

Clothing. US waist sizes are in inches. A 32 is 32 × 2.54 = 81.28 cm, which European labels round to 81 or 82. A 34 is 86.36 cm.

Hardware. A 12-inch subfloor spacing is 30.48 cm; a 6-inch pipe is 15.24 cm. Trade sizes are often nominal rather than actual, so convert the stated figure and then check the real dimension.

Two things worth knowing:

• For a rough figure, multiply by 2.5 and add 2%. 32 inches → 80 → 81.6, against a true 81.28. Close enough to sanity-check a result you have typed in a hurry.
• Fractional inches are still common in the US. A ½ inch is 1.27 cm and a ¼ inch is 0.635 cm, so enter 6.5 rather than "6 1/2".

To convert back, divide centimeters by 2.54 — or flip the converter above.